Carbon nanotubes, which possess unique electrical and mechanical properties, have a high potential applicability to the future nanotechnologies such as field emission electron sources, nanoscale electronic devices, chemical storage systems, and mechanical reinforcement materials.
Since carbon nanotubes were discovered in a cathodic deposit produced with an electric discharge brought about using a carbon electrode in a fullerene forming apparatus, a variety of techniques have been proposed for synthesizing carbon nanotubes. These synthesis techniques aim to be able to produce carbon nanotubes in large quantities and also to synthesize carbon nanotubes having a specific function. Such specific functions are, among others, the function to suspend the catalytic ability for a hydrocarbon, the function to electrolyze a condensate phase and the catalytic function for SiC sublimation. Such carbon nanotubes must have an oriented growth structure that agrees with such a particular function.
The synthesis methods so far proposed have been found, however, to be capable of producing carbon nanotubes only at a yield just enough for them to be used in research and far less than the methods can be applied to their industrial production. Another problem with these prior methods is that the nanotubes aligned thereby on a substrate are weak in their bonding strength with the substrate and are thus hard to handle.
It would be advantageous if carbon nanotubes can be synthesized in large quantities and at a low cost using the most updated Si technology, for example, by the use of a material and equipment employed in the Si semiconductor process. Then, it will be possible to supply at low cost and in bulk nanotechnology products which with the best use of the unique properties of carbon nanotubes are functionally excellent.